Field of the Invention
The present invention relates to wireless communication, and more particularly, to a method and an apparatus for performing active scanning in a wireless communication system.
Related Art
Wi-Fi is a wireless local area network (WLAN) technology that allows a wireless apparatus to access the Internet in a frequency band of 2.4 GHz, 5 GHz, or 60 GHz. The WLAN is based on an Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard.
An IEEE 802.11n standard supports multiple antennas and provides maximum 600 Mbit/s data rate. A system that supports IEEE 802.11n is referred to as a high throughput (HT) system.
An IEEE 802.11ac standard operates primarily in the 5 GHz band and provides data rate of 1 Gbit/s or more. The IEEE 802.11ac supports downlink multi-user multiple input multiple output (DL MU-MIMO). A system that supports IEEE 802.11ac is referred to as a very high throughput (VHT) system.
IEEE 802.11ax is developed as next-generation WLAN for coping with higher data rate and a higher user load. A scope of the IEEE 802.11ax may include 1) enhancement of an 802.11 physical (PHY) layer and a medium access control (MAC) layer, 2) enhancement of spectrum efficiency and area throughput, 3) performance enhancement in an environment in which an interference source exists, a dense heterogeneous network environment, and an environment in which the high user load exists, and the like.
The existing IEEE 802.11 standard just supports only orthogonal frequency division multiplexing (OFDM). However, it is considered that a next-generation WLAN supports orthogonal frequency division multiple access (OFDMA) in which a multiple-user access is available.
A method for forming active scanning and association is required in an OFDMA environment.